As the size of semiconductor devices has continued to shrink and circuit densities have increased accordingly, thermal management of these devices has become more challenging. This problem is expected to worsen in the foreseeable future. Thus, within the next decade, spatially averaged heat fluxes in microprocessor devices are projected to increase by a factor of two, to well over 100 W/cm2, with core regions of these devices experiencing local heat fluxes that are several times higher.
In the past, thermal management in semiconductor devices was often addressed through the use of forced convective air cooling, either alone or in conjunction with various heat sink devices, and was accomplished through the use of fans. However, fan-based cooling systems were found to be undesirable due to the electromagnetic interference and noise attendant to their use. Moreover, the use of fans also requires relatively large moving parts, and corresponding high power inputs, in order to achieve the desired level of heat transfer.
More recently, thermal management systems have been developed which utilize synthetic jet ejectors. These systems are more energy efficient than comparable fan-based systems, and also offer reduced levels of noise and electromagnetic interference. Systems of this type, an example of which is depicted in FIG. 1, are described in greater detail in U.S. Pat. No. 6,588,497 (Glezer et al.).
The system depicted in FIG. 1 utilizes an air-cooled heat transfer module 101 which is based on a ducted heat ejector (DHE) concept. The module utilizes a thermally conductive, high aspect ratio duct 103 that is thermally coupled to one or more IC packages 105. Heat is removed from the IC packages 105 by thermal conduction into the duct shell 107, where it is subsequently transferred to the air moving through the duct. The air flow within the duct 103 is induced through internal forced convection by a pair of low form factor synthetic jet ejectors 109 which are integrated into the duct shell 107. In addition to inducing air flow, the turbulent jet produced by the synthetic jet ejector 109 enables highly efficient convective heat transfer and heat transport at low volume flow rates through small scale motions near the heated surfaces, while also inducing vigorous mixing of the core flow within the duct.
While the systems disclosed in Glezer et al. represent a very notable improvement in the art of thermal management systems, in light of the aforementioned challenges in the art, a need exists for thermal management systems with even greater energy efficiencies. There is also a need in the art for thermal management systems that are scalable and compact, and that do not contribute significantly to the overall size of the device. These and other needs are met by the devices and methodologies described herein.